The hypothesis that nutritional habits in childhood or adolescence (particularly energy and/or fat intake) may be associated with increased prostate cancer risk, possibly mediated through body size and/or weight gain during particular periods of life, is currently receiving increased attention. The purpose of the proposed investigation is to test this hypothesis in a prospective cohort study. To define potential critical exposure periods this study will specifically focus on the age at which dietary restriction took place. This investigation utilizes the unique setting in the Netherlands, a western population where prostate cancer is common. In this country, a substantial part of the population was exposed to a severe famine towards the end (1944-1945) of World War II. In addition, nutrition was compromised, albeit to a lesser degree, during the economic crisis of the 1930s and in the early years of the wartime occupation which started in 1940. In 1986, 58,279 men between the ages 55-69 were recruited for a cohort study on diet and cancer risk in the Netherlands. A substantial number of these men experienced the economic depression and the wartime events in childhood. The impact of these exposures on body size and prostate cancer incidence will be studied, as will the association between childhood nutrition and stage at diagnosis. The results of this investigation will provide highly relevant prospective data on the relation between energy restriction in childhood and subsequent prostate cancer risk in a nationally representative sample of adult men.